2-74362989-C-T

Position:

• chr2-74362989-C-T

Variant summary

Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP6_Very_Strong BS1 BS2

The NM_004082.5(DCTN1):​c.3529+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.00815 in 1,611,326 control chromosomes in the GnomAD database, including 50 homozygotes. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0063 (2 hom., cov: 32)
  • Exomes 𝑓: 0.0083 (48 hom.)
• Consequence: DCTN1 NM_004082.5 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9988
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:13
• Conservation: PhyloP100: 4.89

Genes affected

DCTN1 (HGNC:2711): (dynactin subunit 1) This gene encodes the largest subunit of dynactin, a macromolecular complex consisting of 10 subunits ranging in size from 22 to 150 kD. Dynactin binds to both microtubules and cytoplasmic dynein. Dynactin is involved in a diverse array of cellular functions, including ER-to-Golgi transport, the centripetal movement of lysosomes and endosomes, spindle formation, chromosome movement, nuclear positioning, and axonogenesis. This subunit interacts with dynein intermediate chain by its domains directly binding to dynein and binds to microtubules via a highly conserved glycine-rich cytoskeleton-associated protein (CAP-Gly) domain in its N-terminus. Alternative splicing of this gene results in multiple transcript variants encoding distinct isoforms. Mutations in this gene cause distal hereditary motor neuronopathy type VIIB (HMN7B) which is also known as distal spinal and bulbar muscular atrophy (dSBMA). [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Benign. Variant got -16 ACMG points.

• BP6: Variant 2-74362989-C-T is Benign according to our data. Variant chr2-74362989-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 284990.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-74362989-C-T is described in Lovd as [Benign].
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.00628 (956/152270) while in subpopulation AMR AF= 0.00908 (139/15300). AF 95% confidence interval is 0.00818. There are 2 homozygotes in gnomad4. There are 469 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 956 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DCTN1	NM_004082.5	c.3529+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000628224.3	NP_004073.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DCTN1	ENST00000628224.3	c.3529+5G>A		splice_donor_5th_base_variant, intron_variant		5	NM_004082.5	ENSP00000487279	A1

Frequencies

GnomAD3 genomes AF: 0.00628 AC: 956 AN: 152152 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.00205

Gnomad AMI AF: 0.0175

Gnomad AMR AF: 0.00910

Gnomad ASJ AF: 0.00634

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.000622

Gnomad FIN AF: 0.00717

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00876

Gnomad OTH AF: 0.00861

GnomAD3 exomes AF: 0.00600 AC: 1484 AN: 247518 Hom.: 8 AF XY: 0.00606 AC XY: 812 AN XY: 133938

Gnomad AFR exome AF: 0.00212

Gnomad AMR exome AF: 0.00495

Gnomad ASJ exome AF: 0.00561

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00126

Gnomad FIN exome AF: 0.00777

Gnomad NFE exome AF: 0.00876

Gnomad OTH exome AF: 0.00713

GnomAD4 exome AF: 0.00834 AC: 12175 AN: 1459056 Hom.: 48 Cov.: 32 AF XY: 0.00809 AC XY: 5873 AN XY: 725608

Gnomad4 AFR exome AF: 0.00191

Gnomad4 AMR exome AF: 0.00467

Gnomad4 ASJ exome AF: 0.00575

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00118

Gnomad4 FIN exome AF: 0.00680

Gnomad4 NFE exome AF: 0.00971

Gnomad4 OTH exome AF: 0.00768

GnomAD4 genome AF: 0.00628 AC: 956 AN: 152270 Hom.: 2 Cov.: 32 AF XY: 0.00630 AC XY: 469 AN XY: 74448

Gnomad4 AFR AF: 0.00205

Gnomad4 AMR AF: 0.00908

Gnomad4 ASJ AF: 0.00634

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.000622

Gnomad4 FIN AF: 0.00717

Gnomad4 NFE AF: 0.00876

Gnomad4 OTH AF: 0.00852

Alfa AF: 0.00711 Hom.: 4

Bravo AF: 0.00618

Asia WGS AF: 0.00202 AC: 7 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:13

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:4

Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 08, 2015	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Jul 17, 2020	- -

not provided Benign:3

Benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 13, 2019	- -
Benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Nov 07, 2023	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	DCTN1: BP4, BS2 -

Perry syndrome Benign:2

Benign, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 29, 2024	- -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Inborn genetic diseases Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 28, 2019

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Neuronopathy, distal hereditary motor, type 7B Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

DCTN1-related disorder Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jun 24, 2019

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Neuronopathy, distal hereditary motor, type 7B;C1862939:Amyotrophic lateral sclerosis type 1;C1868594:Perry syndrome Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Uncertain	25
DANN	Benign	0.94

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.88
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs72466494; hg19: chr2-74590116;